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4.0L OHV & SOHC V6 Tech General discussion of 4.0L OHV and SOHC V6 Ford Ranger engines.

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Old 01-27-2007
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Cel P1121

I recently replaced the TPS. If anyone remembers I was having trouble. The truck was shifting very hard. I replaced the TPS and reset the PCM with my code reader and also had the battery disconnected for over 30 minutes. The old thread TPS Problem .

The truck now is running better but my gas mileage is horrible prolly around 12 or 13mpg with my stock tires it should be around 18 or 19. I have code P1121 and my code reader description says "Manufacture controlled fuel and air metering". The truck seems to be idling low. I thought it was because my torque converter was not disengaging but even in neutral it is idling low. Also if in neutral I rev it over 2000rpms and then let off the gas it will stall out.

I plan to replace the fuel filter today because it needs it.
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Old 01-27-2007
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Any code number in your Ranger above P1000 is a Ford-specific code. That's why your universal reader does not have a code definition for it.


P1121: TPS inconsistent with MAF sensor

I haven't seen this one before. The PCM compares the TPS and MAF inputs to see if they make sense. If the values are not consistent, it sets a code and lights the CEL.

Ford gives these as possible causes:

Air leak between MAF sensor and throttle body
TP sensor not seated properly
Damaged TP sensor
Damaged MAF sensor
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Old 01-27-2007
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I will take the TPS off and make sure it is on there right. Is it possible the TPS I got is not functioning correctly. Do I possibly need a new MAF
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Old 01-27-2007
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It could be that the TPS you got is leaky or doesn't fit right. Since that's some of the last work you did, it's a good place to look.

Checking the MAF, connections and so on is good also. Verify the PCV connection also as it can come off and leak as well.

Sometimes you can use the old-school leak-test technique of spraying carb cleaner at a place you suspect a leak and listening for a change in motor operation.
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Old 01-27-2007
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Quote:
Originally Posted by n3elz
Verify the PCV connection also as it can come off and leak as well.
I am not a betting man but This is a good guess and something I hadn't thought of. I will go check it along with the TPS right now. Along with another shot at getting the FUEL Filter off.

I can't get the FUel Filter off. I tried pulling, twisting, prying, and a tool from advance. Still I am dumbfounded at how this thing comes off.
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Old 01-27-2007
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if its anything like my truck.. it requires a special tool to get the Fuel filter off.

I just changed mine 2 weeks ago
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Old 01-27-2007
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I am also guessing it is a PCV leak. Basically what it saying is that your MAF is detecting so much air flow and the TPS is not adjusting correctly. I would clean the MAF for sure which Im thinking is the problem. Otherwise let the engine run and check for a vac leak.
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Old 01-27-2007
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Oh fuel filter will require a fuel line tool.

http://www.explorerforum.com/forums/...d.php?t=102197

Thats an example of a tool that can be used to take it off, how it works is there is a metal O ring holding the connector on, you need to slip the tool between the fuel filter an the Oring to allow the fuel line to slip off.

here are some more tools....

http://www.mytoolstore.com/kd/kdengi04.html#3408

The first tool ive never used, however I have on many occasions used the next 3 style of tools.
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Old 01-27-2007
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Thanks irons now I know I bought the wrong tool. Will have to go back and get the right one.
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Old 01-27-2007
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Well I got the CEL light problem fixed I think anyway. The TPS was not fit on right. I took it off and put it back on adjusting how I put it on slightly. The idle is good and it doesn't stall when reving up and letting it drop. I still have to get the right tool at the autoparts store. I had to quit for the night since we had some company come over.
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Old 01-29-2007
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Quote:
Originally Posted by bryanjints
Well I got the CEL light problem fixed I think anyway. The TPS was not fit on right. I took it off and put it back on adjusting how I put it on slightly. The idle is good and it doesn't stall when reving up and letting it drop. I still have to get the right tool at the autoparts store. I had to quit for the night since we had some company come over.
Well I was wrong. Looks like I have a problem that is going to take some time to get right. After taking the TPS off and putting it back on it idles better it no longer dies if I rev it but now I have the hard shifting again that I had two weeks ago. Also if I floor it it won't shift up to the next gear unless I let off the gas. Then it will shift through the gears real fast like from 2nd through 4th and OD and I will only be going 35mph.

Any more help I am thinking of cleaning the MAF since I have never done that. How can I test the TPS to see if it is working correctly.
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Old 01-29-2007
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Bump for BOB
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Old 01-29-2007
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Quote:
Originally Posted by bryanjints
How can I test the TPS to see if it is working correctly.
With the TPS plugged in normally and the ignition on, measure the voltage across the gray/white (+) and gray/red (-)

Closed throttle voltage should be 0.6~1.2V
Wide open throttle voltage should be less than 4.65V. I think something in the 4.0~4.5V range is common.

Between the closed throttle value and the WOT value, the voltage should rise proportionately as the throttle is opened. In other words, the voltage should increase steadily as the throttle opening is increased without any sudden jumps or reversals along the way.
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Old 01-30-2007
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How do I check that what do I need to do that.


I have 3 codes. P0122 P0123 P1121
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Old 01-30-2007
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Okay more info. The TPS I bought and installed was shot. I compared it to my old one. The old one the inner part turned with resistance but was consistent. The new one had little resistance and also clicked and grinded. I put the old one on because I think that it is better than the new one. The shifting got really crazy today with the new one and when the old one was on there I didn't have as bad as a problem as I did today. today while I was going 45mph the tranny shifted down to 2nd I think. then it wouldn't shift back to 3rd or 4th. So I put the shifter in 2 then back to D and then it shifted luckily this happened within a mile of my house. I am about to go take it for a drive with the old TPS on and when I get back I will post what happens.
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Old 01-30-2007
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Okay more info. Old TPS installed. I cleaned it since it was very dirty. I also sprayed electrical cleaning stuff CRC brand on the connections and in that whole area. Drove several miles. Shifting is normal. The only wierd thing I had was after driving for a while I had a high idle when I restarted it. I tapped the gas and it went down to a normal level. I did not reset the computer. If I have no problems (like the shifting) again tomorrow I will reset the computer and see if I have any other problems.
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Old 02-03-2007
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Quote:
Originally Posted by bryanjints
Okay more info. Old TPS installed. I cleaned it since it was very dirty. I also sprayed electrical cleaning stuff CRC brand on the connections and in that whole area. Drove several miles. Shifting is normal. The only wierd thing I had was after driving for a while I had a high idle when I restarted it. I tapped the gas and it went down to a normal level. I did not reset the computer. If I have no problems (like the shifting) again tomorrow I will reset the computer and see if I have any other problems.
Old TPS definetly broken I am going to get the NEW one I had on there replaced.

Bob your test of the voltage and such I don't know how to do that. Could you clarify that more.
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Old 02-03-2007
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Quote:
Originally Posted by bryanjints
Old TPS definetly broken I am going to get the NEW one I had on there replaced.

Bob your test of the voltage and such I don't know how to do that. Could you clarify that more.
You'll have to figure out a way to monitor those 2 wires using a voltmeter while everything is connected. You may be able to slide small wire strands into the connectors or do some other improvised tap that doesn't damage anything. I don't like the quickie method of tapping through the insulation with pins, especially in an area that is exposed to the elements like the underhood environment. Unless it is thoroughly resealed with "liquid electrical tape" or equivalent, this method can come back to bite you after a few years.

After you get the tap set up, then turn the key to 'ignition on' and measure the voltage. Note the value at closed throttle and wide open throttle, then look for a smooth increase in voltage as the throttle goes slowly form closed to open.
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Old 02-03-2007
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Spray uncolrinated brake cleaner on the MAF or whatever you used on your TPS and buy a fully working TPS. This should solve all ur problems.
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Old 02-05-2007
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SOLUTION: make sure the TPS you buy is the one made for your engine. The one I got from NAPA was for the 4cylinder not 4Liter. Oh well I went back to exchange it and will get a new one tomorrow. he had to order it.
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